PROJECT SUMMARY/ABSTRACT. In recent years, mutations in PTEN-induced kinase 1 (PINK1) have been associated with autosomal recessive Parkinsonism. Early studies have uniformly shown a neuroprotective role for PINK1, indicating that studying this familial form of PD may offer valuable insights into potential therapeutic strategies. Dysregulation of mitochondria and autophagy are both centrally implicated in toxin, genetic and environmental approaches to modeling PD. Our preliminary data implicate PINK1 in the upstream regulation of autophagy and in maintenance of mitochondrial interconnectivity, neurite health and synaptic function. Using differentiated neuronal cell lines and primary neuron cultures from control and PINK1 knockout mice, we will determine mechanisms by which PINK1 protects from toxin and genetic PD models, focusing on: 1) the role of subcellular localization in PINK1-mediated neuroprotection, 2) mechanisms regulating PINK1 localization, and 3) identification and characterization of downstream components of the PINK1 signaling pathway, using both candidate and nonbiased proteomic approaches. Achieving the goals of this project to obtain a better understanding of PINK1 regulation, subcellular compartmentalization and downstream pathways will provide insight into new therapeutic strategies to reduce neuronal dysfunction and cell death in PD.